Promoting structural distortion to enhance the crystal field strength of Mn(ii) in tetrahedral bromide for near-unity yellow emission

Two zero-dimensional hybrid manganese bromide polymorphs ((DMAPH)₂MnBr₄) exhibit single-crystal to single-crystal phase transformation, accompanied by an increase in MnBr₄ tetrahedral bond angle variance (σ²). This structural change leads to an emission redshift due to enhanced crystal field strength, achieving yellow emission with near-unity quantum yield, which highlights its potential for solid-state lighting applications.